A supporting structure within a furnace chamber where temperatures may be in the order of 2000.degree. F. must be compact in order to leave sufficient combustion space in the chamber, must be strong enough to support heavy metal work pieces being treated in the furnace, and must be protected against injury by the high temperature within the furnace while at the same time not seriously interfering with the efficiency and maximum temperature of a furnace. It must also be strong enough to withstand the stresses and heavy vibration set up by the movement of the heavy work pieces within the heating chamber.
Refractory insulating materials have been used for a number of years in the production of cast insulating bodies required to line heat treating furnaces and insulate supporting structures within the interior of heat treating furnaces. More recently the advantageous insulating properties attainable by use of suitable fibrous insulating materials have become recognised, and it has been desired to find ways of utilising these materials to produce insulating members for use in heating furnaces and the like. However, the structural strength of these materials is low and does not meet all service conditions.